<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <style>
            * {
                margin: 0;
                padding: 0;
                box-sizing: border-box;
            }
            .kuang {
                position: fixed;
                top: 0;
                left: 0;
                width: 100%;
                height: 100%;
                z-index: -10;
                background-image: linear-gradient(180deg, rgb(78, 168, 241), rgb(37, 91, 241));
            }
            .bubble {
                position: absolute;
                border-radius: 50%;
                border: 2px solid #fff;
                box-shadow: inset 0 0 8px #fff;
                animation: flutter 10s infinite;
                opacity: 0;
            }
            @keyframes flutter {
                0% {
                    transform: translateX(0);
                    bottom: -100px;
                    opacity: 1;
                }
                50% {
                    transform: translateX(100px);
                    opacity: 0.5;
                }

                100% {
                    transform: translateX(0px);
                    bottom: 100%;
                    opacity: 0;
                }
            }
            .bubble:nth-child(1) {
                left: -10%;
                width: 50px;
                height: 50px;
                animation-duration: 9s;
                animation-delay: 0.1s;
            }
            .bubble:nth-child(2) {
                left: 15%;
                width: 20px;
                height: 20px;
                animation-duration: 6s;
                animation-delay: 1.5s;
            }
            .bubble:nth-child(3) {
                left: 20%;
                width: 60px;
                height: 60px;
                animation-duration: 10s;
            }
            .bubble:nth-child(4) {
                left: 30%;
                width: 30px;
                height: 30px;
                animation-duration: 5.5s;
                animation-delay: 1.5s;
            }
            .bubble:nth-child(5) {
                left: 40%x;
                width: 50px;
                height: 50px;
                animation-duration: 12s;
            }
            .bubble:nth-child(6) {
                left: 50%;
                width: 20px;
                height: 20px;
                animation-duration: 6s;
                animation-delay: 1s;
            }
            .bubble:nth-child(7) {
                left: 60%;
                width: 40px;
                height: 40px;
                animation-duration: 8s;
                animation-delay: 1s;
            }
            .bubble:nth-child(8) {
                left: 65%;
                width: 60px;
                height: 60px;
                animation-duration: 15s;
            }
            .bubble:nth-child(9) {
                left: 80%;
                width: 55px;
                height: 55px;
                animation-duration: 9s;
                animation-delay: 0.5s;
            }
            .bubble:nth-child(10) {
                left: 100%;
                width: 40px;
                height: 40px;
                animation-duration: 12s;
            }
        </style>
    </head>
    <body>
        <div class="kuang">
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
            <div class="bubble"></div>
        </div>
    </body>
</html>
